Pharmacology is the study of drug action. It involves looking at the interaction of chemical substances with the systems in our bodies, as well as identifying ways in which our biological systems affect drugs.
the branch of medicine concerned with the uses,
effects, and modes of action of drugs.
Pharmacology is the study of drug action. It
involves looking at the interaction of chemical
substances with the systems in our bodies, as well
as identifying ways in which our biological systems
Pharmacology is the branch
of biology concerned with the study
of drug action, where a drug can be
broadly defined as any man-made,
natural, or endogenous (from within
the body) molecule which exerts a
biochemical or physiological effect on
the cell, tissue, organ, or organism.
It is the art of preparing, compounding, and dispensing
drugs. The word also refers to the place where drugs are
prepared and dispensed.
The science or practice of the preparation and dispensing
of medicinal drugs.
5. Clinical pharmacist
Is a specialist who often guides the physician in
A clinical pharmacists provide direct patient care that
optimizes the use of medication and promotes health,
wellness, and disease prevention
6. Clinical pharmacist
While regular pharmacists normally work in a pharmacy,
a clinical pharmacist works directly with medical
professionals and patients, usually in a medical center,
hospital or health care unit. The job of the clinical
pharmacist is to determine the best medications for a
given symptom for a patient at a given time.
A medication is a substance administered for the
diagnosis, cure, treatment, or relief of a symptom or for
prevention of disease. In the health care context, the
words medication and drug are generally used
Medications have been known and used since antiquity.
Crude drugs, such as opium, castor oil, and vinegar, were
used in ancient times. Over the centuries the number of
drugs available has increased greatly, and knowledge
about these drugs has become correspondingly more
accurate and detailed.
In the United States, medications are usually dispensed on
the order of primary care providers and dentists. In some
U.S. states, specially qualified nurse practitioners or other
advanced practice nurses and physician assistants may
The written direction for the preparation and
administration of a drug is called a prescription.
One drug can have as many as four kinds of names: its
1. generic name,
2. trade name,
3. official name, and
4. chemical name.
12. Drugs vary in strength and activity.
Drugs derived from plants, for example, vary in strength
according to the age of the plant, the variety, the place in
which it is grown, and the method by which it is
Drugs must be pure and of uniform strength if drug
dosages are to be predictable in their effect.
Drug standards have therefore been developed to ensure
13. These drugs are officially listed in the United States
Pharmacopeia (USP) and described according to their
source, physical and chemical properties, tests for purity
and identity, method of storage, assay, category, and
14. Effects of Drugs
The therapeutic effect of a drug, also
referred to as the desired effect, is the
primary effect intended, that is, the
reason the drug is prescribed.
16. Effects of Drugs
Aside effect, or secondary effect, of a
drug is one that is unintended. Side effects
are usually predictable and may be either
harmless or potentially harmful.
17. Effects of Drugs
A side effect, or secondary effect,
of a drug is one that is
unintended. Side effects are
usually predictable and may be
either harmless or potentially
18. Effects of Drugs
Drug toxicity (deleterious effects of a
drug on an organism or tissue) results
from over dosage, ingestion of a drug
intended for external use, or buildup of
the drug in the blood because of
impaired metabolism or excretion
19. A drug allergy is an immunologic
reaction to a drug. When a client
is first exposed to a foreign
substance (antigen), the body
may react by producing
Effects of Drugs
20. A severe allergic reaction usually
occurs immediately after the
administration of the drug and is
called an anaphylactic reaction.
The earliest symptoms are a subjective
feeling of swelling in the mouth and tongue,
acute shortness of breath, acute
hypotension, and tachycardia.
Effects of Drugs
21. Effects of Drugs
Drug tolerance exists in a person
who has unusually low
physiological response to a drug
and who requires increases in
the dosage to maintain a given
22. Effects of Drugs
A cumulative effect is the
increasing response to repeated
doses of a drug that occurs when
the rate of administration exceeds
the rate of metabolism or
23. Effects of Drugs
An idiosyncratic effect is one
that is unexpected and may be
individual to a client.
Underresponse and overresponse
to a drug may be idiosyncratic.
24. Effects of Drugs
A drug interaction occurs when the
administration of one drug before, at the
same time as, or after another drug alters
the effect of one or both drugs.
!!Drug interactions may be beneficial or harmful.
25. Effects of Drugs
The effect of one or both drugs may be
either increased (potentiating effect)
or decreased (inhibiting effect).
26. Effects of Drugs
When two of the same types of drug
increase the action of each other, the
effect is known as additive.
A synergistic effect occurs when two
different drugs increase the action of one
or another drug.
27. Effects of Drugs
Iatrogenic disease (disease caused
unintentionally by medical therapy)
can be due to drug therapy.
29. Types of Drug Preparation
Aerosol spray or foam
A liquid, powder, or foam deposited in
a thin layer on the skin by air pressure
One or more drugs dissolved in water
30. Types of Drug Preparation
One or more drugs finely divided in a
liquid such as water
A solid form, shaped like a capsule,
coated and easily swallowed
31. Types of Drug Preparation
A gelatinous container to hold a drug in
powder, liquid, or oil form
A non greasy, semisolid preparation used
on the skin
32. Types of Drug Preparation
A sweetened and aromatic solution of
alcohol used as a vehicle for medicinal
A concentrated form of a drug made from
vegetables or animals
33. Types of Drug Preparation
Gel or jelly
A clear or translucent semisolid that
liquefies when applied to the skin
A medication mixed with alcohol, oil,
or soapy emollient and applied to the
34. Types of Drug Preparation
A medication in a liquid suspension
applied to the skin
A flat, round, or oval preparation that
dissolves and releases a drug when held
in the mouth
35. Types of Drug Preparation
Ointment (salve, unction)
A semisolid preparation of one or more drugs
used for application to the skin and mucous
A preparation like an ointment, but thicker
and stiff, that penetrates the skin less than
36. Types of Drug Preparation
One or more drugs mixed with a cohesive
material, in oval, round, or flattened
A finely ground drug or drugs; some are
used internally, others externally
37. Types of Drug Preparation
One or several drugs mixed with a firm base
such as gelatin and shaped for insertion into
the body (e.g., the rectum); the base
dissolves gradually at body temperature,
releasing the drug
An aqueous solution of sugar often used to
disguise unpleasant-tasting drugs
38. Types of Drug Preparation
A powdered drug compressed into a hard small
disc; some are readily broken along a scored line;
others are enteric coated to prevent them from
dissolving in the stomach
An alcoholic or water-and-alcohol solution
prepared from drugs derived from plants
39. Types of Drug Preparation
A semipermeable membrane shaped in the form of a disc or
patch that contains a drug to be absorbed through the skin
over a long period of time
A client tells the nurse, “This pill is a
different color than the one that I usually
take at home.” Which is the best response
by the nurse?
1. “Go ahead and take your medicine.”
2. “I will recheck your medication orders.”.
3. “Maybe the doctor ordered a different
4. “I’ll leave the pill here while I check
with the doctor.”
Proper administration of an otic
medication to a 2-year-old client
includes which of the following?
1. Pull the ear straight back.
2. Pull the ear down and back.
3. Pull the ear up and back.
4. Pull the ear straight upward
42. Drug Misuse
Drug misuse is the improper use of common
medications in ways that lead to acute and
Both OTC drugs and prescription drugs may be
Laxatives, antacids, vitamins, headache
remedies, and cough and cold medications are
often self-prescribed and overused
43. Drug Misuse
Most people suffer no harmful effects from these drugs, but
some people do. For example, a client might use an OTC
cough medicine to treat a cough that might be caused by a
serious underlying problem such as throat cancer.
44. Drug Misuse
is an inappropriate intake of a substance,
either continually or periodically.
By definition, drug use is abusive when
society considers it abusive.
45. Drug Misuse
Drug abuse has two main facets, drug
dependence and habituation.
Drug dependence is a person’s reliance on
or need to take a drug or substance.
The two types of dependence, physiological
and psychological, may occur separately or
46. Drug Misuse
Physiological dependence is due to
biochemical changes in body tissues,
especially the nervous system. These
tissues come to require the substance for
47. Drug Misuse
Psychological dependence is emotional reliance on a drug
to maintain a sense of wellbeing, accompanied by feelings
of need or cravings for that drug.
48. Drug Misuse
Drug habituation denotes a mild form
of psychological dependence.
The individual develops the habit of
taking the substance and feels better
after taking it. The habituated
individual tends to continue the habit
even though it may be injurious to
49. Drug Misuse
Illicit drugs (also called street drugs)
These are those sold illegally. Illicit drugs
are of two types:
(a) drugs unavailable for purchase under
any circumstances, such as heroin (in the
United States), and
(b) drugs normally available with a
prescription that are being obtained
through illegal channels.
50. Actions of Drugs on the Body
The action of a drug in the body can be
described in terms of its half-life, the time
interval required for the body’s elimination
processes to reduce the concentration of the
drug in the body by one-half.
51. Actions of Drugs on the Body
For example, if a drug’s half-life is 8 hours, then the
amount of drug in the body is as follows:
After 8 hours: 50%
After 16 hours: 25%
After 24 hours: 12.5%
After 32 hours: 6.25%
52. Actions of Drugs on the Body
Because the purpose of most drug therapy is to maintain a
constant drug level in the body, repeated doses are
required to maintain that level. When an orally
administered drug is absorbed from the gastrointestinal
tract into the blood plasma, its concentration in the
plasma increases until the elimination rate equals the rate
54. Key terms related to drug actions are as
■ Onset of action: The time after administration when the body initially
responds to the drug
■ Peak plasma level: The highest plasma level achieved by a single dose
when the elimination rate of a drug equals the absorption rate
■ Drug half-life (elimination half-life): The time required for the
elimination process to reduce the concentration of the drug to one-half
what it was at initial administration
■ Plateau: A maintained concentration of a drug in the plasma during a
series of scheduled doses.
Notas del editor
Toxicology: is the study of the adverse effects that various chemicals,
It is the study of the effect of drugs on living organisms.
The term drug also has the connotation of an illicitly obtained substance such as heroin, cocaine, or amphetamines.
trade name (or brand name)
The generic name is assigned by the United States Adopted Names (USAN) Council and is used throughout the drug’s lifetime.
trade name (sometimes called the brand name) is the name given by the drug manufacturer and identifies it as property of that company. If patented
Official name is the name under which a drug is listed in one of the official publications (e.g., the United States Pharmacopeia)
The chemical name is the name by which a chemist knows it
In the United States, official drugs are those so designated by the federal Food, Drug, and Cosmetic Act.
Apharmacopoeia (also spelled pharmacopeia) is a book containing
a list of products used in medicine, with descriptions of the
product, chemical tests for determining identity and purity, and
formulas and prescriptions.
Pharmacopoeias and formularies are invaluable reference
sources for nurses and nursing students.
digitalis increases the strength of myocardial contractions (desired effect), but it can have the side effect of inducing nausea and vomiting
more severe side effects, also called adverse effects or reactions,
Allergic reactions can be either mild or severe. Amild reaction
has a variety of symptoms, from skin rashes to diarrhea
Drugs that commonly produce tolerance are opiates, barbiturates, and ethyl alcohol.
As a result, the amount
of the drug builds up in the client’s body unless the dosage is adjusted.
Toxic symptoms may occur
Potentiating effects may be additive or synergistic.
Hepatic toxicity resulting in biliary obstruction, renal damage, and malformations of the fetus as a result of specific drugs taken during pregnancy are examples.
To straighten the ear canal in children less than 3 years of age, the ear must be pulled down and back. In individuals over 3 years of age, the ear is pulled up and back
For example, the intake of alcohol at work may be considered alcohol abuse, but intake at a social gathering may not.
A dependent person who stops using the drug experiences withdrawal symptoms
Illicit drugs often are taken because of their mood-altering effect; that is, they make the person feel happy or relaxed.